A message of size 1,200,000 bits is sent from source to destination through a…

Given Data

• Message size = 1,200,000 bits

• Packet size = 12,000 bits

• Number of links = 4

• Transmission rate of each link = 3 Mbps=3×106 bps

• Switching technique = Store-and-Forward Packet Switching

• Propagation and processing delays are ignored.

Step 1: Find Number of Packets

Step 1: Find Number of Packets

Number of packets = 1,200,000 / 12,000 = 100 packets

Step 2: Transmission Time of One Packet on One Link

Step 3: Time for First Packet to Reach Destination

In store-and-forward switching, a packet must be completely received before forwarding to the next link.

There are 4 links, therefore first packet requires:

4×4 ms = 16 ms

Step 4: Time for Remaining Packets

After the first packet, packets move in pipelined fashion.

Each additional packet reaches destination after one packet transmission time:

4 ms

Remaining packets:

100−1=99

Additional time:

99×4 ms = 396 ms

Final Answer

0.412 seconds​

Hence, the total time required to deliver the complete message is:

412 ms